[Radiance-openstudio] OpenStudio on OSX 10.8

[Guglielmetti, Robert]

Hi Khalid,

You are right, metric was a poor choice of words regarding the DF. I also
agree that tools should allow architects to quickly estimate the impacts
of their designs, and that controls are crucial to any daylighting system
delivering a cost-effective solution. But lighting controls cannot be
simulated with a DF analysis because the performance of such systems is
highly dependent on actual daylight distributions within a space. This is
the main driver for us in integrating Radiance with OpenStudio (and, in
turn, EnergyPlus). 

It is our hope that eventually OpenStudio will make it relatively painless
to do a much more thorough daylighting analysis than EnergyPlus is capable
of on its own. 
 

Rob Guglielmetti
National Renewable Energy Laboratory (NREL)
Commercial Buildings Research Group
15013 Denver West Parkway MS:RSF202
Golden, CO 80401
303.275.4319
robert.guglielmetti at nrel.gov






On 11/16/12 2:42 AM, "Khalid" <khalid.ud at gmail.com> wrote:

>Thanks Rob, for the information.
>Regarding the Daylight Factor, the following discussion was in a paper I
>read several years ago;
>	"the average daylight factor .. is a useful design aid which is also
>simple to use. Since the daylight distribution and intensity inside the
>building will vary with time, whichever sky distribution is used as a
>basis
>for design, then it would seem that great precision in this is
>unnecessary..............  I have strong reservations over the provision
>of
>detailed and complex daylight prediction system. What is required, in my
>opinion, is a relatively simple system that architects must be encouraged
>to
>use and to combine this with the provision of daylight controls to adjust
>the daylight conditions when necessary. Electronic control of the electric
>lighting 	should then  integrate the electric lighting with the
>daylighting for an energy-efficient design." (David Loe, in the discussion
>in reference (1)).
>As an architect I believe the daylight factor is more than a metric, and I
>do think that its use in different climatic conditions could be improved.
>
>Thanks
>
>1- Kittler 1994 Kittler R. The Need for Standard Skies and Models for
>Energy
>Conservation Measures. Lighting Research and Technology
>1994;26(4):171-180.
>
>
>-----Original Message-----
>From: Guglielmetti, Robert [mailto:Robert.Guglielmetti at nrel.gov]
>Sent: Friday, November 16, 2012 7:11 PM
>To: Discussion of Radiance with OpenStudio
>Subject: Re: [Radiance-openstudio] OpenStudio on OSX 10.8
>
>Hi Khalid,
>
>Actually, if you check the "Use Radiance..." box in OpenStudio, then
>Radiance will be used for all the daylighting calculations. That's why
>it's
>important to review the "radout.sql" file for the daylighting data, when
>Radiance is used.
>
>The sky condition is derived automatically from the weather file. This is
>the beauty of what John Mardaljevec calls "climate based daylight
>modeling",
>or CBDM. The sky condition for each timestep is based on the Perez
>all-weather sky model, which simply takes direct normal and diffuse
>horizontal flux (irradiance or illuminance) as input. It is the ratio of
>those two values that dictates the sky condition.
>
>Daylight factors are computed from overcast sky daylight availability
>only.
>This misses a lot of prevalent sky conditions, and as such is a pretty
>useless metric for many climates. Hence, the move to CBDM which we have
>embraced in OpenStudio (as have Christoph Reinhart, Alstan Jakubiec, and
>Kera Lagios with DIVA, Rick Mistrick with the new DAYSIM, et al.).
>
>Are we having fun yet, Khalid? =8-)
>
>Rob Guglielmetti
>National Renewable Energy Laboratory (NREL) Commercial Buildings Research
>Group
>15013 Denver West Parkway MS:RSF202
>Golden, CO 80401
>303.275.4319
>robert.guglielmetti at nrel.gov
>
>
>
>
>
>
>On 11/15/12 10:53 PM, "Khalid" <khalid.ud at gmail.com> wrote:
>
>>Hi, Rob
>>Regarding the sky condition in radiance which come with openstudio, is
>>there is a way to select the type of sky condition (clear, overcast,
>>...) As far as I knew the illuminace map will be generated by
>>EenergyPlus based on the weather file, is there is a way have the
>>result as a function of sky type, as done in daylight factor
>>Calculation?
>>
>>Thanks
>>-----Original Message-----
>>From: Rob Guglielmetti [mailto:rob.guglielmetti at gmail.com]
>>Sent: Thursday, November 15, 2012 4:13 AM
>>To: Discussion of Radiance with OpenStudio
>>Subject: Re: [Radiance-openstudio] OpenStudio on OSX 10.8
>>
>>Hi Khalid,
>>
>>THat would be great if you're willing to give it a try! I don't know
>>that there are a lot of people trying out the Linux version. Ubuntu is
>>what we develop and test on, too.
>>
>>- Rob
>>
>>ease Date: 11/14/12
>>
>>
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>
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